import freezeObject from '../Core/freezeObject.js';
import WebGLConstants from '../Core/WebGLConstants.js';

    /**
     * Enumerates all possible filters used when minifying WebGL textures.
     *
     * @exports TextureMinificationFilter
     *
     * @see TextureMagnificationFilter
     */
    var TextureMinificationFilter = {
        /**
         * Samples the texture by returning the closest pixel.
         *
         * @type {Number}
         * @constant
         */
        NEAREST : WebGLConstants.NEAREST,
        /**
         * Samples the texture through bi-linear interpolation of the four nearest pixels. This produces smoother results than <code>NEAREST</code> filtering.
         *
         * @type {Number}
         * @constant
         */
        LINEAR : WebGLConstants.LINEAR,
        /**
         * Selects the nearest mip level and applies nearest sampling within that level.
         * <p>
         * Requires that the texture has a mipmap. The mip level is chosen by the view angle and screen-space size of the texture.
         * </p>
         *
         * @type {Number}
         * @constant
         */
        NEAREST_MIPMAP_NEAREST : WebGLConstants.NEAREST_MIPMAP_NEAREST,
        /**
         * Selects the nearest mip level and applies linear sampling within that level.
         * <p>
         * Requires that the texture has a mipmap. The mip level is chosen by the view angle and screen-space size of the texture.
         * </p>
         *
         * @type {Number}
         * @constant
         */
        LINEAR_MIPMAP_NEAREST : WebGLConstants.LINEAR_MIPMAP_NEAREST,
        /**
         * Read texture values with nearest sampling from two adjacent mip levels and linearly interpolate the results.
         * <p>
         * This option provides a good balance of visual quality and speed when sampling from a mipmapped texture.
         * </p>
         * <p>
         * Requires that the texture has a mipmap. The mip level is chosen by the view angle and screen-space size of the texture.
         * </p>
         *
         * @type {Number}
         * @constant
         */
        NEAREST_MIPMAP_LINEAR : WebGLConstants.NEAREST_MIPMAP_LINEAR,
        /**
         * Read texture values with linear sampling from two adjacent mip levels and linearly interpolate the results.
         * <p>
         * This option provides a good balance of visual quality and speed when sampling from a mipmapped texture.
         * </p>
         * <p>
         * Requires that the texture has a mipmap. The mip level is chosen by the view angle and screen-space size of the texture.
         * </p>
         * @type {Number}
         * @constant
         */
        LINEAR_MIPMAP_LINEAR : WebGLConstants.LINEAR_MIPMAP_LINEAR,

        /**
         * Validates the given <code>textureMinificationFilter</code> with respect to the possible enum values.
         *
         * @private
         *
         * @param textureMinificationFilter
         * @returns {Boolean} <code>true</code> if <code>textureMinificationFilter</code> is valid.
         */
        validate : function(textureMinificationFilter) {
            return ((textureMinificationFilter === TextureMinificationFilter.NEAREST) ||
                    (textureMinificationFilter === TextureMinificationFilter.LINEAR) ||
                    (textureMinificationFilter === TextureMinificationFilter.NEAREST_MIPMAP_NEAREST) ||
                    (textureMinificationFilter === TextureMinificationFilter.LINEAR_MIPMAP_NEAREST) ||
                    (textureMinificationFilter === TextureMinificationFilter.NEAREST_MIPMAP_LINEAR) ||
                    (textureMinificationFilter === TextureMinificationFilter.LINEAR_MIPMAP_LINEAR));
        }
    };
export default freezeObject(TextureMinificationFilter);
